This is a combined clinical and laboratory study evaluating the efficacy of intrapleural BCG as an anti-tumor agent. The unique feature of the study is the emphasis on regional administration. Patients with resected lung cancer are treated shortly after surgery with intrapleural BCG and followed at regular intervals. A significant benefit has been found in Stage I patients. In future studies, all Stage I patients will receive intrapleural BCG and a new test group will receive supplemental cutaneous BCG. Using an experimental lung tumor model, the augmentation of the BCG effect induced by INH will be explored, emphasizing the influence of BCG plus INH on pleural macrophages.